COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY SCHEDULE OF AIRWORTHINESS DIRECTIVES Casa 212 Series Aeroplanes AD/CASA/6 Fuel Shut-Off Valves - Replacement 9/83 Applicability: All Casa 212 models as referenced in requirement document. Document: Casa SB No. 212-28-15. Compliance: Before further flight after 31st August 1983. Background: The manufacturer advises that failures have been discovered in the operation of fuel shut-off valves.